Cognitive scientist donald a. norman (1988) identified three different features of a conceptual model that interface designers must consider. what are these three features

The three features are The Visceral Design, The Behavioral Design, and The Reflective Design.  Visceral mentions to the “gut” in this instance. It’s a reference to the perception of “gut instinct”. It’s an unintentional level of response to definite experiences.  Though, to get to the behavioral design we have to pass over the visceral design test first. The reflective design is plentiful more subtle than the first two but equally significant if we want our designs to have lasting value for our users. 

the correct answer is modern american cars are not available due to trade restrictions.

trade between cuba and the united states have serious restrictions. the u.s. imposed an economic embargo on cuba, that among other things means that modern american cars are not available due to trade restrictions.

in response to some governmental actions of the authorities from cuba, president john f. kennedy proclaimed an embargo on trade between both countries in february 1962. the trade embargo remains active until this day and was implemented directly by the departments of commerce and the department of treasury.

in president trump’s administration, there is a national security presidential memorandum that "strengthens the policy of the u. s.", affecting trade with cuba.

  b.

there are isolated pockets of farming, generally around rivers and oases, which are used for irrigation.